So I’m using two of those logic level shifters for the 6 3.3-5V channels, which is a waste of 2 channels. As I’m running out of space, I would like to cut down the third levle shifter to just one channel.

After studying the traces on both sides of the PCB, it looks to that its possible to:

cut off the last channel, which is not really usefull as it doesn’t save much space and its easy to damage another channel: